(also outbound traffic)
Egress traffic definition
Egress traffic refers to the data leaving a system or a network. It originates from within the system and goes to an external destination, whether it’s other networks, servers, or clients. Egress traffic is the opposite of ingress traffic, which is the incoming data flow. It may include various data types, such as requests to access websites, emails sent to external recipients, or data transfers. Managing and monitoring egress traffic is crucial for ensuring optimal network performance, controlling bandwidth-related costs, and maintaining network and system security and integrity. For instance, it can reveal potential security risks, unauthorized data exfiltration, or malicious activities.
Egress traffic use cases
- Data exfiltration detection. Monitoring egress traffic can help identify unusual patterns on a system or network. It can detect and protect against unauthorized data transfers or leakage, indicating potential insider threats or compromised systems.
- Command and control (C2) traffic detection. Analyzing egress traffic helps identify connections to known malicious IPs, domains, or unusual communication patterns, which can signal the presence of malware or an ongoing cyberattack.
- Bandwidth management. Monitoring egress traffic can help identify excessive bandwidth usage, which can also be caused by unauthorized activities, and cut costs.
- Policy enforcement. Implementing security policies and restrictions on egress traffic can help prevent unauthorized access to external resources and reduce the attack surface. For instance, specific ports, protocols, or destinations can be blocked or web filtering and application control can be implemented.
- Network segmentation. By restricting traffic between different network segments, the risk of lateral movement can be minimized, preventing attackers from gaining access to sensitive data.